Regex to check a string

Question

Hi, I'm trying to check a string and then extract all the variables which starts with @. I can't find the appropriate regular expression to check the string. The string may start with @ or " and if it's started with " it should have a matching pair ".

Example 1:

"ip : "+@value1+"."+@value2+"."+@value3+"."+@value4

Example 2:

@nameParameter "@yahoo.com"

Thanks

Answer 1

It would probably be easiest to first split the string on each quoted string, then check the unquoted parts for @'s. For example all quoted strings could be: /"[^"]*"/, calling Regex.Split on your string would return an array of strings of the non-quoted parts, which you could then use the expression /@\w+/ to find any @'s.

Answer 2

Try this:

string text = "@nameParameter \"@yahoo.com\"";
Regex variables = new Regex(@"(?<!"")@\w+", RegexOptions.Compiled);
foreach (Match match in variables.Matches(text))
{
    Console.WriteLine(match.Value);
}

Answer 3

To check the strings you have provided in your post:

(^("[^"\r\n]"\s+@[\w.]+\s*+?)+)|(((^@[\w.]+)|("@[\w.]+"))\s*)+